1. Field of the Invention
This invention pertains to apparatus for filling drums and other containers with a liquid.
2. Description of the Related Art
Drums and other containers are commonly filled by machines having lances which may extend into the containers for delivering the liquid into the containers. Depending upon the nature of the liquid, the distal end or tip of the lance may be positioned either above or below the surface of the liquid during a filling operation. With liquids which tend to foam or produce fumes or noxious odors, the liquid is generally introduced at a relatively slow or "dribble" rate initially with the tip of the lance near the bottom of the container. Once the level of the liquid has risen above the tip of the lance, the flow rate can be increased, and the tip of the lance is maintained below the surface of the liquid for the remainder of the filling operation. This type of filling operation is known as subsurface filling. With other liquids, disturbance of the liquid during a filling operation is not a problem, and the lance can remain in the upper portion of the container. This type of filling operation is known as top filling. With either type of filling operation, the filling rate is generally decreased as the level of the liquid approaches the top of the container to prevent over filling and spillage of the liquid.
The amount of liquid which is delivered to a container and the rate at which it is introduced can be controlled either manually or automatically. A manually controlled system has the advantage of being somewhat simpler and less expensive to install, but it requires more time and attention on the part of the operator. An automated system is generally more expensive initially, but it is generally more economical to operate.
One example of an automated system for subsurface filling operations is described in U.S. Pat. No. 4,337,802.
It is in general an object of the invention to provide new and improved apparatus for filling drums and other containers with a liquid product.
Another object of the invention is to provide apparatus of the above character which overcomes at least some of the limitations and disadvantages of drum fillers heretofore provided.
Another object of the invention is to provide apparatus of the above character which is economical to manufacture and easy to operate.